Apparatus for sealing envelopes



Feb. 2, 1965 R. v. DORN ETAL 3,

APPARATUS FOR SEALING ENVELOPES Filed Nov. 16, 1961 4 Sheets-Sheet 1 Fl ENVELOPE SPACER 1 Q AND SEPERATORZ? POSTAGE FEED AND A mxmq MEQHANVSM 26 f /3 ENVELOPE SEALER 25 IN VEN TORS- RONALD V. DORN @EUBEN R. LOGAN Feb. 2, 1965 R. v. DORN ETAL APPARATUS FOR SEALING ENVELOPES 4 Sheets-Sheet 2 Filed Nov. 16, 1961 AAN INVENTORSZ RONALD V. DORN REUBEN R. LO BY Feb. 2, 1965 R. v. DORN ETAL APPARATUS FOR SEALING ENVELOPE-S 4 Sheets-Sheet 5 Filed Nov. 16, 1961 5 N 1 m fly VOL ,{H o. v M mm MM As ,4 Nu oz 55m Feb. 2, 1965 R. v. DORN ETAL APPARATUS FOR SEALING ENVELOFES 4 Sheets-Sheet 4 Filed Nov. 16, 1961 B M ma mi in MR DN WW 8 REM United States Patent Ofitice 3,168,428 Patented Feb. 2, 1965 APPARATUS FOR SEALING ENVELOPES Ronald V. Dem, 315 14th St. NW., Albuquerque, N. Mex

and Reuben R. Logan, 4251 Zenith Ave. N., Robbinsdale, Minn, assignors of thirty percent to Reuben R. Logan and seventy percent to Ronald V. Dom

Filed Nov. 16, 1961, Ser. No. 152,852 4 (Ilaims. (Cl. 156-442) This invention relates to a new and improved apparatus for sealing envelopes, and more particularly to an envelope sealing apparatus that is suitable for inclusion in a general purpose mailing machine. This application is a continuation-in-part of our application Serial No. 667,382, filed June 24, 1957, now abandoned.

A variety of different mechanisms have been proposed and used for sealing envelopes, either in separate envelope sealing devices or in mailing machines that perform other functions such as affixing postage to the envelope. In many such machines, the flap of the envelope must be displaced from the body portion of the envelope before initiation of the sealing operation; that is, the envelopes must be completely open at the time that they are fed through the sealing mechanism. In other machines, it is necessary that the envelopes be shingled, the envelopes being nested together with each flap separated from the body portion of the envelope by the intervening flap portion of the next envelope in the stack. In either arrangement, some difiiculty may be encountered in re-folding the envelopes accurately along the desired fold line or in jamming of the operating mechanism, particularly where a shingling operation is incomplete at some point in the stack. Moreover, shingling can be an expensive and time-consuming operation.

It is a principal object of the present invention, therefore, to provide a new and improved envelope sealing mechanism that operates consistently, and at high speeds, yet which does not require that the envelopes be opened or shingled.

A related object of the invention is to provide a new and improved envelope sealing mechanism that operates with a minimum opening of the envelope from its normal folded condition.

Another object of the invention is to provide a new and improved envelope sealing apparatus that will accept envelopes of substantially diiferent configurations and sizes, particularly with respect to variations in flap shape.

Another object of the invention is to provide a new and improved envelope sealing apparatus particularly adapted for incorporation in a mailing machine that is also utilized to afiix postage to the envelope. To this end, one feature of the present invention is the provision of a convenient by-pass mechanism that permits envelopes or other mailing pieces to be moved through the sealing apparatus without being subjected to a sealing operation.

Other and further objects of the present invention will be apparent from the following description and claims and are illustrated in the accompanying drawings which, by way of illustration, show a preferred embodiment of the present invention and the principles thereof and what is now considered to be the best mode contemplated for applying these principles. Other embodiments of the invention embodying the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention and the purview of the appended claims.

In the drawings:

FIG. 1 is a simplified elevation view of a general purpose mailing machine, with the covers removed, in which the envelope sealing apparatus of the present invention may be incorporated;

FIG. 2 is a plan view of a first embodiment of the invention;

FIG. 3 is an elevation view of the apparatus of FIG. 2;

FIG. 4 is an elevation view of an envelope sealing apparatus constructed in accordance with a preferred embodiment of the present invention;

FIG. 5 is a plan view of the envelope sealing apparatus;

FIG. 6 is similar to FIG. 4 but showing the sealer in a by-pass operating condition;

FIG. 7 is a plan view of the wick of the envelope sealing apparatus; and

FIG. 8 is a detail elevation view of the wick structure.

The general purpose mailing machine 10 illustrated in FIG. 1 is essentially similar to that described and claimed in the co-pending application of Ronald V. Dorn and Reuben R. Logan, of which the present application constitutes a continuation-in-part. The machine 10 comprises a suitable housing 11, a portion of which has been removed to show the internal operating elements of the mailing machine. A back frame 13 is provided in the machine and an upper front frame member 12 is mounted at the near side of the machine as seen in FIG. 1. The front frame member 12 may be mounted on the back frame member 13 by suitable cantilever supports or the like (not shown). A lower front frame member 14 (FIG. 4) may also be included in the machine and may be rigidly connected to the back frame member 13 by suitable connecting frame members.

A feed table 17 extends longitudinally of the machine 10, the left-hand portion of the table 17 being utilized to support a stack of envelopes as generally indicated by the reference numeral 16. Conveyor means are provided for driving the envelopes or other mailing pieces from the stack 16 through the machine 10, the envelopes moving from left to right as seen in FIG. 1. In the machine shown in FIG. 1, the conveyor means comprises one or more conveyor belts 18 that are engaged by a drive roller 19 and which extend into engagement with a plurality of individual idler rollers 2044. For the most part, the conveyor belts 18 extend across the surface of the table 17, but a portion of the conveyor is located below the table, adjacent the idler 21, to permit incorporation in the machine of an envelope sealer apparatus constructed in accordance with the present invention. The envelope sealing apparatus is generally identified by the reference numeral 25. To the right of the envelope sealer 25, in the machine 10, are located the postage feed and affixing mechanisms 26, which are shown only generally in FIG. 1. Between the envelope stack 16 and the envelope sealer 25, on the other hand, there is located an envelope separator and spacer mechanism 27. The separator and spacer mechanism 27 and the postage feed and aifixing mechanism 26 do not constitute part of the present invention and, accordingly, are not shown in detail. The present invention is concerned with the envelope sealer mechanism 25. The envelopes 16 with which the present invention operates are of the conventional type having closure flaps coated with a moisture-softenable adhesive, as will be apparent from the following description.

In operation of the machine 10, individual envelopes or mailing pieces are fed from the bottom of the stack 16 along the table 17 by means of the conveyor belts 18. The spacer and separator mechanism 27 prevents the feeding of more than one mailing piece at a time. The device 27 also spaces the individual envelopes to provide a definite gap between them as they move through the machine 10. This is important in order to prevent sealing the envelopes to each other and to permit each mailing piece to control operation of the postage feed and affixing mechanism 26. From the spacer and separator 27, each envelope passes through the sealer 25, which would normally seal the envelopes. However, and as pointed out more fully hereinafter, the sealer 25 may be provided with means to by-pass the sealing operation, permitting 3 each mailing piece to pass through without being scaled. As the envelopes continue their movement through the machine 10, postage is affixed to each by the mechanism 26. The envelopes are discharged from the machine .11) at the right-hand side thereof as seen in FIG. 1.

The initial embodiment of the envelope sealer mecha-' nism may best be understood by reference to FIGS. 2 and 3. As indicated in FIG. 2, the table 17 is provided with an aperture 35 within which an inclined ramp 79 is mounted. The inclined ramp 7 is of cantilever construction and is supported by means of an extension 1112 atfixed to the upper front frame member 12 as by bolts or other suitable means. The ramp extends transversely of the path of the envelope movement within the machine and terminates short of the rear vertical guide, frame member 13, as indicated in FIG. 2. Thus, a clearance space is afforded between the rear edge 103 of the ramp 79 and the fold line 160 of the envelope 1613 as the envelope advances through the sealer 25.

The configuration of the ramp 79 is such as to'alford a leading or flap-engaging edge 104 which extends across the machine at an acute angle to the perpendicular to the direction of envelope movement, indicated in FIG. 2 by the arrow A. This leading edge 104 of ramp 79 is made relatively thin, since it is utilized to separate the envelope fiap 16C from the body of the envelope 16B during the initial portion of the sealing operation. The effective height H of the leading edge 1624 is preferably made long enough to exceed the height of the flap on any envelope to be processed in the machine.

A first pair of brackets 195 are mounted beneath the ramp 79 adjacent the central portion thereof; .a similar pair of brackets 196 are mounted beneath the ramp in alignment with the brackets 105 at the opposite side of the ramp. The brackets 105 and 106 are utilized to support a moistener 167 immediately below ramp 79. The moistener 107 comprises a metal cartridge 108 which partially encompasses a wick member 109, the lower surface 112 of the wick member 109 being exposed beneath the ramp 79 in position to contact the gumrned surface of the envelope flap 16C. The wick member 109 extends beyond the cartridge member 108 into a reservoir 80 which may be an integral part of the cartridge 108 or may constitute a separate reservoir. A handle 110 is affixed t the reservoir 80 to provide for convenient insertion or removal of the cartridge. The choice of wicking for the member 109 is not critical, since the wick is required to raise water from the reservoir 80 through only a relatively short distance; the wick may, for example, be fabricated from ordinary cotton felt or any other suitable wicking material.

Before the machine is placed in operation, the reservoir is filled with water and the water is drawn up into the wick 109 by capillary action in the usual manner, thereby moistening the wick. In some instances, it may be desirable to pro-moisten the upper part of wick member 109 before the machine is first placed in operation. As an envelope is advanced through the machine in the direction indicated by arrows A in FIG. 2, it encounters the leading or blade edge 16-4 of the ramp 72. The blade edge 104 deflects the envelope flap 16C downwardly away from the body of the envelope as best indicated in FIG. 2. Consequently, the adhesive-coated upper surface of the envelope flap brushes against the lower surface 112 of the wick member 109 and is moistened by water drawn into the wick from the auxiliary reservoir 80. Preferably, only a fractional portion of the envelope flap is separated from the envelope body at .any given time; as a consequence, the flap is not deflected from the envelope body through a distance sufficient to cause it to miss contact with the wick. The separation angle between the envelope body and flap is relatively small, thereby avoidingany difficulty in bringing the flap and envelope body back together in sealing relationship.

After the envelope 16B advances beyond the trailing 4 edge 114 of the ramp 79, it is caught between the conveyor belts 18 and an upper pressure roller 98 at a point immediately above the conveyor roller 22 (FIG. 1).

t The roller 28 is biased toward pressure contact with the conveyor roller 22 at this point, and the body and flap portions of the envelope are pressed together, thereby sealing the moistened flap to the envelope body. In many instances, the rolling pressure afforded at this point of the machine would be sufiicient to complete the sealing operation. With some envelope adhesives, however, the initial pressure afforded by roller 98 is insufiicient to complete the sealing operation, since the adhesive may not soften rapidly enough to permit complete sealing immediately after the moistening operation. Effective scaling is assured, however, by the further rolling pressure contact afforded by the subsequent engagement of the envelope by a pressure roller 10% which engages the envelope to press the fiap and body portions thereof toframe members 12 and 13.

gether a second time as the envelope leaves the machine.

The flap opening, envelope sealing, and by-pass mechanism comprising a preferred embodiment of the invention is illustrated in FIGS. 4 through 8. As shown in FIGS. 2-4, a spacer frame 265 is mounted between the Immediately below the spacer frame 265 the table 217 is cut away in order to permit the rollers 26 to project upwardly through the table. To the right of the rollers 20, as seen in FIG. 5,

there is a portion of the table 217 that affords a flap opener blade, this blade being identified generally by the reference character 230,. Starting at the top of FIG. 5, near the back edge of an envelope 16X advancing through the machine, it is seen that the flap opener blade 230 affords two connected angular edge surfaces 231 and 233, the edge 233' terminating in a projection 232. The position of the envelope entering the sealer is determined by a guide 263. The under-surface of the edge 233 is beveled to aiford a'knife edge for opening the envelope flaps as described hereinafter. It should also be noted that the rear portion of the table 217 comprising the blade 23%, is bent upwardly from approximately the line 271, the rise being shown also in FIG. 4. The conjunction of the two edge surfaces 231 and 233 is identified by the reference numeral 264.

A stud 241 is mounted on the back frame member 13 projecting inwardly of the machine. The stud 241 is utilized to carry a pair of flap control arms that determine the operation of the envelope sealing mechanism. One of these arms is the flap opener arm 243, the other being the flap by-pass arm 242. The flap opener arm 243 is shown in detail in FIGS. 4-6. It comprises an upper stop portion 244 that is positioned to engage one surface of the frame member 205 (see FIG. 4). The flap opener arm further includes an extension portion which terminates in a downwardly projecting foot 245 that extends outwardly of the flap opener arm in an upwardly bent element 246. The lowermost point or toe of the flap opener arm is identified by the reference numeral .247. With the arm 243 in its normal operating position, .as shown in FIG. 4, the toe 247 of the arm is located slightly below the point 264 on the blade 23%. A bras spring 254 is connected to the extension portion of the arm 243 that carries the foot 245, the other end of the spring 254 being connected to a shaft 219. This bias spring normally maintains the arm 243 in the position shown in FIG. 4.

The by-pass arm 242 is somewhat similar in configuration to the flap opener arm 243. It includes a stop element 248 in position to engage the frame member 205 (see FIG. 4). It also includes an extension portion that pro ects outwardly and downwardly and terminates in a foot having two angularly related portions or elements 249 and 251. In the normal position of the arm 242, as shown in FIG. 4, the elements 249 and 251 are located below the table 217 and out .of contact with any part of the envelope.

A yoke 255 is included in the by-pass mechanism, this yoke being pivotally mounted upon a pair of axially aligned pins constituting two studs 257 and 258 that are mounted in the frame members 13 and 12 respectively. The by-pass yoke 255 includes a handle portion 256 that projects outwardly beyond the end of the upper front frame member 12. At the other end of the yoke, a spring 259 is connected to the yoke, the opposite end of the spring being connected to a stud 261 that is mounted on and projects inwardly from the back frame member 13. As shown in FIG. 4, the spring 259 is located above the pivotal axis of the yoke, established by the studs 257 and 258, to afford a toggle action as described hereinafter. That is, the spring 259 tends to hold the yoke 255 in the position shown in FIG. 4 or in a secondary position to which the yoke may be pivoted to by-pass the envelope sealer 225, as shown in FIG. 6.

T o the right of the blade 230, and below the stable 217, there is mounted a moistener 286. The moistener includes a wick cartridge 281 slidably mounted in suitable brackets 282 (FIGS. 4 and 6). The cartridge 281 carries a wick 266. A pressure plate 275 is pivotally mounted on a stud 276, the pressure plate including a curved pressure foot 283 that extends beneath the wick 266. A relatively weak spring 277 biases the pressure plate 275 toward the position shown in FIGS. 4 and 6.

The wick cartridge 281 is substantially T-shaped in configuration, as shown in FIG. 7. The top of the T covers a corresponding portion of the wick 266, which terminates in two depending Wick branches 285 and 286 (FIG. 8). A clip 287 may be used to hold the wick branches 285 and 286 in spaced relation to each other. The wick branches extend into a water reservoir (not shown) and are used to increase the total effective capacity of the wick 266. A relatively heavy felt block 289 is interposed between the wick branches 285 and 286 to provide an improved water supply.

In considering operation of the flap opening, envelope sealing and by-pass mechanism 225 of FIGS. 4-8, it may be assumed that an envelope 16X is moving along the conveyor belts 18 in the direction of the arrow X and has reached the position shown in FIG. 5. The envelope rides between the belts and suitable hold-down rollers 90 (FIG. 1), that have been omitted in the detail figures to avoid masking the sealer parts. Hence, the envelope is above the projecting portion 232 of the blade 230 that comprises a part of the machine table 217. As the envelope continues its advancing movement, the leadng edge of the envelope is engaged by the toe 247 on the lower end 246 of the flap opener arm 243. The arm 243, as noted above, is held in the position shown in FIG. 4 by the spring 254, the movement of the arm in a clockwise direction about the stud 241 being limited by engagement of the stop element 244 of the arm with the frame member 205. Moreover, and as noted above, the toe portion 247 of the flap opener arm is located below the advance point 264 of the blade 230, which is the first point on the blade that engages the envelope flap. The point 264 of the blade, as noted above, is elevated with respect to the lower portion of the table 217, as seen in FIGS. 4 and 6, the blade being bent upwardly slightly about the line 271 (FIG. 5). Consequently, the fold portion of the envelope, comprising the flap, is forced downwardly by the toe 247, below the leading point 264 of the blade 230. It is important that the point of engagement of the toe 247 with the envelope be displaced inwardly of the fold edge of the envelope, since otherwise the envelope may merely be bent downwardly as a whole and separation of the flap from the body of the envelope may not be achieved.

The movement of the envelope 16X in the direction of the arrow X causes the blade 230, and specifically the knife edge portion 233 of the blade, to deflect the flap downwardly away from the under surface of the table. The envelope flap is engaged on its lower surface by the pressure plate 275 that is pivotally mounted on the stud 276. The spring 277 biases the pressure plate 275 toward counterclockwise rotation, as seen in FIGS. 4 and 6, tending to press the pressure plate 275 upwardly toward the wick 266. Consequently, the envelope flap is forced into engagement with the wick 266 by the pressure plate 275 and is moistened by contact with the wick. The continued movement of the envelope passes the envelope be tween the pressure rollers, as described in connection with the embodiment of FIGS. 2 and 3, to seal the envelope.

Certain features of the configuration of the flap opener blade 230 are of substantial advantage in preventing tearing of the envelope flap or other malfunctions of the sealing mechanism. The radius 234 on the sharpened portion 233 of the blade is provided to pull down the lower part of the flap (FIG. 5) and prevent it from catching on the projecting portion 232 of the blade. However, this radius is not necessary if the projection 232 is not required and if the beveled knife edge 233 is continued beyond the maximum limit for height of the flap of the envelope. It is preferable to continue the beveled construction along the edge 231 to reduce the possibility of catching the corner portion of the envelope flap and jamming or tearing the same. As noted above, the relatively sharply angular edge 231 on the blade is utilized to provide initial engagement with the envelope flap at the point 264, which is spaced from the back fold edge of the envelope. This construction is of particular importance Where the sealing mechanism is to be used with envelopes having relatively square flap corners at the fold edge of the envelope.

In a given instance, it may be desrable to pass envelopes through the machine without sealing the envelopes. This is particularly true if previously sealed envelopes are to be conveyed through the machine, since the envelope sealing mechanism may tend to catch in the corner portions of these sealed envelopes and to open the envelopes or mutilate them. Under these circumstances, the handle 256 is utilized to pivot the by-pass yoke 255 approximately about the pins 257 and 258 from the position of FIG. 4 to that of FIG. 6. The pivotal movement of the yoke is limited by engagement thereof with the surface 267 on the end of the upper front frame member 12. As the yoke is pivoted to this position, the right-hand end of the spring 259 is pivoted to a location below the line of centers of the studs 257, 258 and the stud 261, so that the spring holds the yoke in the new position.

As the yoke 255 is turned to its alternate position, as described above, it engages the surfaces 272 and 273 of the arms 242 and 243 respectively. The continued pivotal movement of the yoke pivots both of the arms 242 and 243 in a counterclockwise direction about the axis established by the stud 241. The pivotal movement of the flap opener arm 243 is such that the foot portion 246 is elevated well above the upper surface of the blade portion 230 of the machine table. The spacing between the lowermost point or toe 247 on the flap opener arm 243 and the top of the table is established at a distance sufiicient to clear any envelope that would normally be passed through the machine (FIG. 4). Thus, if an envelope is passed through the machine with the arm 243 pivoted as described above, and with the toe .247 located well above the blade 230, the envelope is not pressed downwardly to force the flap below the blade.

The pivotal movement of the bypass arm 242, occasioned by action of the yoke 255 as described above, moves the upper surface of the foot 249 on the bypass arm a small distance above the point 264 on the flap opener blade 230. This distance may, for example, be of the order of inch. Consequnetly, when an envelope is fed through the machine, the leading edge of the envelope rides up on the element 251 of the by-pass arm 242 and over the connecting surface element 249. In this manner, the lower surface of the envelope is deflected upwardly away from the blade 230 just enough to prevent any envelope flap or projection from catch.- ing on the blade. Consequently, the envelope is passed through the machine without 'being sealed. Furthermore, if a pre-sealed envelope is passed through the machine under these conditions, it is prevented from catching on the flap opener blade and any damage which might othe wise result is avoided.

Hence, while preferred embodiments of theinven-tion have been described and illustrated, it is to be understood that they are capable of variation and modification, and we therefore do not wish to be limited to the precise details set forth, but desire to avail ourselves of such changes and alterations as fall Within the purview of the following claims.

We claim:

1. An envelope sealing mechanism for sealing individual envelopes, of the kind having moisture-scftenable adhesive coated closure flaps, moving one-by-one in flap- :folded position along a given path in a predetermined plane, with the fold edges of the envelopes aligned with each other parallel to the path, at one edge thereof, comprising: a cantilever blade projecting transversely of the path of envelope movement, approximately in said plane, in position to deflect the flap from the body of the envelope through an acute angle, said blade terminating short of said one edge of the envelope path; means, com prising a yieldable flap opener member located adjacent said one edge of the envelope path, for deflecting each envelope, inwardly of its fold edge, toward said blade, in adirection transverse to said plane, immediately ahead of the free end of said blade; .a moistener mounted on the flap-side of said blade in position to moisten the inner surface of each flap as it passes said blade; and means for pressing the flap and body portions of the envelopes together as each envelope moves beyond the blade.

2. An envelope sealing mechanism for sealing individual envelopes, of the kind having moisture-soften-able adhesive coated closure flaps, moving one-'by-one in flapfold d position along a given path in a predetermined plane with the fold edges of the envelopes aligned with each other parallel to the path, at one edge thereof, comprising: a cantilever blade projecting transversely of the path of envelope movement, approximately in said plane, in position to deflect the flap from the body of the envelope through :an acute angle, said blade terminating short of said one edge of the envelope path, the free end of said blade being inclined at a small angle to said plane to deflect the fold edge of each envelope from said plane, through a short distance toward the body side of the envelope; yieldable means, at said one edge of the envelope path, for deflecting each envelope, inwardly of its fold edge, toward the flap side of the envelope, immediately ahead of :the free end of said blade; a wick moistener mounted on the flap-side of said blade in position to engage and moisten the inner surface of each flap as it passes said blade; and means for pressing the flap and body portions of the envelopes together as each envelope movesbeyond the blade.

3. An envelope sealing mechanism for sealing individual envelopes of the kind having moisture-softenable adhesive coated closure flaps, comprising: means for moving the envelopes in flap-folded position along a given path in a predetermined substantially horizontal plane,

with the fold edges of the envelopes aligned with each other parallel to the path, at one edge thereof and with the flaps disposed beneath the envelopes; a cantilever blade projecting transversely of the path of envelope movement, approximately in said plane, in position to deflect the flap from the body of the envelope downwardly through an acute angle, said blade terminating short of said one edge of the envelope path, the leading edge of the major portion of said blade, starting at the fixed end of the blade, extending at an acute angle to the nor.- mal to said path away from the oncoming envelopes, the free end portion of the leading edge of said blade extending away from the oncoming envelopes at a substantially greater angle; means, comprising a yieldable flap opener member located adjacent said one edge of the envelope path, for deflecting each envelope, inwardly of its fold edge, toward said blade, in a direction transverse to said plane, immediately ahead of the free end of said blade; a moistener mounted on the flap-side of said blade in position to moisten the inner surface of each flap as it passes said blade; and means for pressing the flap and body portions of the envelopes together as each envelope moves beyond the blade.

4. An envelope sealing mechanism for sealing individual envelopes of the kind having moisture-softenable adhesive coated closure-flaps, comprising: means for moving the envelopes one-by-one in flap-folded position along a given path in a predetermined substantially horizontal plane, with the fold edges of the envelopes aligned with each other parallel to the path, at one edge thereof, and with the flaps disposed beneath the envelopes; an angular cantilever blade projecting transversely of the path of envelope movement, approximately in said plane, in position to deflect the flap from the body of the envelope downwardly through an acute angle, said blade terminating short of said one edge of the envelope path; a moistener mounted on the flap-side of said blade in position to moisten the inner surface of each flap as it passes said blade; a yieldable flap opener member, located adjacent said one edge of the envelope path, and movable between a first operating position in which said opener member projects into the path and deflects each envelope, inwardly of its fold edge, toward said blade, and a second operating position in which said opener member is displaced from said envelope path; a guide member, located adjacent said one edge of the envelope path, and movable between a first operating position in which the guide member guides the envelope flap toward said moistener, and a second operating position in which the guide member projects into the envelope path ahead of the blade and guides each envelope over the blade without flap separation; a by-pass actuating member for moving said flap opener and guide members conjointly between their respective first and second operating positions; and means for pressing the flap and body portions of the envelopes together as each envelope moves beyond the blade.

References Cited in the file of this patent UNITED STATES PATENTS 1,421,867 Vidaver July 4, 1922 1,547,537 Vidaver July 28, 1925 1,566,635 Vidaver Dec. 22, 1925 1,593,867 Cleveland July 27, 1926 2,939,261 Calhoun June 7, 1960 

1. AN ENVELOPE SEALING MECHANISM FOR SEALING INDIVIDUAL ENVELOPES, OF THE KIND HAVING MOISTURE-SOFTENABLE ADHESIVE COATED CLOSURE FLAPS, MOVING ONE-BY-ONE IN FLAPFOLDED POSITION ALONG A GIVEN PATH IN A PREDETERMINED PLANE, WITH THE FOLD EDGES OF THE ENVELOPES ALIGNED WITH EACH OTHER PARALLEL TO THE PATH, AT ONE EDGE THEREOF, COMPRISING: A CANTILEVER BLADE PROJFECTINGTRANSVERSELY OF THE PATH OF ENVELOPE MOVEMENT, APPROXIMATELY IN SAID PLANE, IN POSITION TO DEFLECT THE FLAP FROM THE BODY OF THE ENVELOPE THROUGH AN ACUTE ANGLE, SAID BLADE TERMINATING SHORT OF SAID ONE EDGE OF THE ENVELOPE PATH; MEANS, COM- 